<div class="loading-wave">
  <div class="loading-bar"></div>
  <div class="loading-bar"></div>
  <div class="loading-bar"></div>
  <div class="loading-bar"></div>
</div>

<style>
/* From Uiverse.io by mrpumps31232 - Tags: loader, wave */
.loading-wave {
  width: 300px;
  height: 100px;
  display: flex;
  justify-content: center;
  align-items: flex-end;
}

.loading-bar {
  width: 20px;
  height: 10px;
  margin: 0 5px;
  background-color: #3498db;
  border-radius: 5px;
  animation: loading-wave-animation 1s ease-in-out infinite;
}

.loading-bar:nth-child(2) {
  animation-delay: 0.1s;
}

.loading-bar:nth-child(3) {
  animation-delay: 0.2s;
}

.loading-bar:nth-child(4) {
  animation-delay: 0.3s;
}

@keyframes loading-wave-animation {
  0% {
    height: 10px;
  }

  50% {
    height: 50px;
  }

  100% {
    height: 10px;
  }
}

</style>
